Functional and expression profiling of DREB genes in Ma Bamboo (Dendrocalamus latiflorus Munro) reveals their role in abiotic stress adaptation

Ma bamboo (Dendrocalamus latiflorus Munro) is a key giant bamboo in South Asia, highly sensitive to abiotic stresses. Dehydration-Responsive Element-Binding (DREB) transcription factors (TFs) are an important gene family involved in plant growth, metabolic regulation, and environmental responses. Although the roles of DREB TFs in plant growth, metabolic regulation, and environmental responses are well studied, little is known in Ma bamboo. To address this gap, we systematically identified and functuonally predicted DREB genes in Ma bamboo, with emphasis on their potential involvement in stress response mechanisms. Through genome-wide analysis, 42 DlDREBs distributed across 6 subfamilies were identified. Integrative analyses encompassin cis-element, chromosomal localization, phylogenetic relationships, protein-protein interaction (PPI) network, and gene ontology (GO) annotations revealed their putative roles in developmental processes, metabolic modulation, and stress adaptation. RT-qPCR profiling demonstrated that eight DlDREBs exhibit distinct and stress-specific expression patterns under cold, salt, and drought treatments, underscoring their pivotal contributions to abiotic stress resilience. Three candidate genes (DREB9-A, DREB10-B, and DREB12-C) were prioritized for functional validation. Subsequent cloning, sequence characterization, subcellular localization analysis, and DNA binding assays confirmed their regulatory potential. Notably, DREB10-B, and DREB12-C were found to directly bind the promoter of GA2ox7, a key gene implicated in abiotic stress signaling, suggesting their mechanistic role in stress-responsive pathways. Furthermore, transient transformation assays in tobacco and yeast transformation experiments demonstrated that overexpression of DREB10-B and DREB12-C may enhance plant stress tolerance. In summary, this study provides a theoretical basis for clarifying the molecular mechanism of the abiotic stress responses of the DREB gene family in Ma bamboo.